Psychological perspective of orthodontic patients due to malocclusion and treatment is less explored in orthodontics until recently. Use of psychometric tools is the method to measure this intangible dimension of malocclusion and treatment. However, many generic and condition-specific tools are available now for this purpose. Patient-reported outcome measures (PROMs) will supplement normative outcome measures in the future and will remain an important aspect in patient-centered orthodontic care. In general, with the use of these tools, there has been a conflicting report regarding the effect of malocclusion on a person's Oral Health-Related Quality of Life (OHRQoL). However, orthodontic treatment has shown consistently to improve OHRQoL though there is a transient worsening in the initial phases of treatment. The effect of self-esteem and psychosocial well-being as mediators influencing OHRQoL and contextual factors such as socioeconomic status and family support mechanism on QoL need further evidence from long-term studies.

Background: Nanohydroxyapatite-silica (nanoHA-Silica) has been produced by one-pot sol-gel technique. The material when incorporated into commercial Glass Ionomer Cement (GIC) was found to exhibit higher Vickers hardness, compressive strength, and flexural strength compared to conventional GIC. However, before starting to be used and exposed to the human cell, every material product should undergo for genotoxic evaluation. Thus, the objective of this in vitro study was to evaluate the genotoxicity of locally produced nanoHA-Silica under bacterial reverse mutation assay (Ames test). Materials and Methods: Four Salmonella typhimurium strains TA98, TA102, TA1535, and TA1537 were incubated with nanoHA-Silica in the presence and absence of exogenous metabolic activation system (S9) at five different concentrations (0.3125, 0.625, 1.25, 2.5, and 5 mg/plate) along with appropriate positive and negative controls. The assessment of the results was based on the number of revertant colonies in each plate, and the results were regarded as mutagenic when the number of revertant colonies was more than two-fold of the negative control. Results: There was no significant increase in the number of revertant colonies corresponding to the increase in the concentrations of the test substance for all the five bacterial strains treated with or without S9. Conclusion: NanoHA-Silica-GIC was non-genotoxic and had no mutagenic potential under present test conditions.

Evaluation of the core thickness and resin cement on the fracture strength of zirconia-based multilayer computer-aided design/computer-aided manufacturing ceramic crowns

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Idris Kavut, Safak KülünkDOI:10.4103/dmr.dmr_33_18

Aim: The purpose of this study was to evaluate the effect of thickness of zirconia core and different resin cements on the fracture strength of veneered zirconia crowns designed by multilayer technique. Materials and Methods: Forty metal dies were constructed to replica maxillary molar. Forty zirconia cores (Sirona inCoris ZI) were designed and constructed (inLab 4.4) with different thicknesses. The thickness of zirconia core was selected as 0.5 and 0.7 mm. Forty Feldspathic ceramic (VITABLOCS Mark II) veneers were fabricated (inLab 4.4) onto the zirconia cores. The zirconia cores were divided into two subgroups, and veneers were cemented with one of the following resin cement: self-cure, self-adhesive resin cement with light-cured option (Multilink N), and a dual-cure resin cement (Panavia F 2.0). Then, crowns were cemented to the metal dies. All the specimens were subjected to thermal cycling 5000 times (5°C–55°C ± 2°C, immersion time: 30 s). A universal testing machine was used for fracture strength test at a crosshead speed of 1 mm/min. The data were analyzed with one-way analysis of variance (α = 0.05). Stereomicroscopy was used to evaluate the failure modes and surface structure. Results: Zirconia core thickness and resin cement material affected the fracture strength (P < 0.05). Increase in core thickness increased the fracture strength of multilayer veneer crown (P < 0.05). Higher fracture strength values were obtained with light-cured, self-adhesive cement in both core thicknesses. Conclusion: Although 0.5-mm thickness zirconia cores showed lower flexural strength, it was higher than the maximum loads which may occur clinically (Fmax= 600 N on one tooth). Furthermore, light-cured, self-adhesive resin cement is advisable to increase the fracture strength with different core thickness.

Introduction: The aim of this in vitro study was to evaluate the efficacy of 50 ug/ml silver nanoparticle (AgNPs), 70 ug/ml AgNPs and 5.25% sodium hypochlorite (NaOCl) as a final irrigant for rapid chair-side decontamination of artificially infected gutta-percha (GP) with Escherichia coli.Materials and Methods: A series 120 GP cones size 40 were taken from new batch. The GP cones were divided into six experimental group: Group I - Evaluation of the contamination of GP cones in manufacturer's Box-(20 GP cones), Group II - Evaluation of GP artificially contaminated with E. coli(100 GP cones), Group III - Evaluation of the effectiveness of 50 ug/ml of AgNPs for decontamination of the cones contaminated with E. coli(n = 20 GP infected cones from Group II), Group IV - Evaluation of the effectiveness of 70 ug/ml of AgNPs for decontamination of the cones contaminated with E. coli(n = 20 GP infected cones from Group II), Group V - Evaluation of the effectiveness of 5.25% NaOCl for decontamination of the cones contaminated with E. coli(n = 20 GP cones infected from Group II). Aliquots from the experimental GP cones were plated on brain heart infusion agar (HiMedia Lab, Mumbai, India), and the colony-forming units were evaluated under colonimeter. Results: 70 ug/ml of AgNPs, 5.25% NaOCl exhibited similar antimicrobial effect (P = 1). Highly significant difference were found when 50 ug/ml compared with 70 ug/ml and 5.25% NaOCl (P < 0.0001). Conclusion: 70 ug/ml of AgNPs (0.007%) proved to be highly effective against E. coli and showed similar antimicrobial efficacy as 5.25% NaOCl at 750 times lesser concentration.

Background: Periodontal health in women is affected by sex hormones. Puberty, menstruation, use of oral contraceptives, pregnancy, and menopause influence the periodontal health in women. Aim: This study was conducted to assess the awareness of oral health changes during menstruation in adolescent girls. Materials and Methods: A self-administered cross-sectional survey was conducted at a node in Navi Mumbai to assess the awareness of adolescent school-going girls on the subject of menstruation and the oral changes associated with the same. Results: Majority of the participants were aware of menstruation and associated problems, but only 4% of participants were aware that oral health changes can occur during menstruation. Conclusion: There is a definite lacuna in the awareness of adolescents about menstruation and the oral health changes associated with the same, and creating awareness on this association is necessary to prevent periodontal disease in adulthood.